Personally, I don't advance solely because of the money. My main motivation is facing and overcoming new challenges. I've worked for a couple startups and another small company. In my experience I face challenges at the start and overcome them while leaving my imprint. Soon after, things are better then when I showed up and the place starts feeling stale. I suppose I just hunger for more punishment. :p The increases in pay are just an added bonus that makes the other stuff in life slightly easier.